Method of casting type faces, stereotype, etc.



Patented Feb. 7, 19 33 7 PAUL EMMITT WHITE, F LANCASTER, OHIO I un'rnonor cA's'rIne TYPE reons-s'rnnno'rvrn, ETC.

No Drawing. 7

The invention herein described has to-do' primarily with the printingart, although the apparatus may be used in other arts Where conditionsand results would be similar, therefore I do not wish to limit the scopeof this invention orits application to that branch of the printing artherein used to illustrate my invention, although the apparatus andmethod as hereindisclosed isparticularly adapted to that'branch'ofprintingembracing the casting of type or stereotype and the like.

Heretofore in the ycasting of stereotype from a stereotype mat greatlosses have 00- curred and much valuable time has been consumed in thecasting of the stereotypeplates from a mat thathas been previously usedor froma mat which has become warped or distorted or from a freshly mademat.

Further, it is not uncommon for a mat to absorb moisture in varyingdegrees over-its face or surface whereby steam or gases are evolved whenthe hotmetal is cast thereon causing a blurring orimperfections that aretroublesome and unsatisfactory.

Again, it is well known by those skilled in the art thatcertain typefaceswill produce a cleaner cut and better printing face from astereotype'mat than will others where the ordinary procedure of castingthe stereotype is followed. V

Further, it is difficult to obtain a clearcut casting of a picture evenfrom the first pouring on a new mat by the. usual method andsubstantiallyimpossible to get 'a satisfactory casting from an oldorused mat, whereas castings made by my improved method are moreperfectly defined, clearer cut and free from smudges', cold shots andother imperfections.

These three faults are particularly annoying and at times are the causeof delays and a loss of time which is invaluable. 7

My method of casting fluid metals for the purpose of obtaining accuratereproduction of the mat surface and the results as alsothe problem inthecastingof stereotype or type faces is quite different from that wherethe interior of the metal is required to be homogeneous, and in theinvention here disclosed one is required to deal with only the exteriorsurface of the casting irrespective of its homo Application filedDecember 4, 1930. Serial No. 500,134.

geneity and density and for this reason the amplitude and frequency ofthe vibrations transmitted to the metal during casting and during thecooling of the metal to the point of solidification are of primeimportance in that by my herein disclosed method I overcome the power ofsurface tension and because of the continued cooling of the metal theresulting increase of viscosity which prevents the metal from flowinginto minute recesses and lines depressions .or acute'angles ofconfiguration.

Because of the character of the material fromwhich the mat or moldsurface is formed, 1 it is desirable to make castingsof type metal at aslow a temperature as is possible and obtain perfect typefaces therebypreserving the mat andalso reducing the loss of metal by oxidation .andformation of dross, but when the ordinaryprocedure is followed it is notan infrequent occurrence that, because of the variation and character ofthe letters and impressions in the mat, it is'necessary to raise thetemperature of the metal 50 or possibly 7 5 above normal or the meantemperature at which the major portion ofthe surfaces would be cast andthis usually results in decreasing the life of the mat and in someinstances totally destroying the same or making it unusable to obtainfurther castings.

N ow my invention consists of a means for rapidly vibrating the castingbox or foundation thatcarries the mold mat and I have found that thiscan best be accomplished by applying one or more of the ordinaryelectric 35 vibrators or modifications thereof to the casting box, asisused in vibrating sand molds or the patterns soprevalently used infoundry practice. To carry out my method I arrange one or more'of theseelectric vibrators on a desirable part of the casting box so that whenthe same is put in operation it produces a vibration of the metalcasting box which is transmitted to the mat. I have foundin'certaininstances that it is desirableto'use'a special form of thesevibrators, one that is so" constructed as to permit regulating the forceas also the frequency of the blow.

deem it unnecessary todescribe in de mil the'construction of thevibrating'appara-tus for I can use, with varying degrees of elficiency,any of the common or well known foundry vibrators, therefore, it seemsunnecessary to illustrate the manner of applying the vibrator to thecasting box. I believe that I can adequately describe the method ofusing the vibrator and the results flowing therefrom as the apparatus isso universally used and so varied in construction that a detailedillustration of construction is unnecessary.

Now referring to the defects above enumerated, the efiect of myinvention in overcoming them is as follows:

Very annoying and harmful but prevalent condition is met when the mat iswarped and does not lie down in a perfect plane or in contact with thecasting box frame, however, when the operator starts to pour the metalinto the gate he actuates a switch and starts the vibrator and thesevibrations together with the weight of molten metal forces the mat intocontact with the plane surface of the casting box plate therebyproducing a lettered surface that is sharp and uniform.

Further, vibrating the mold frame and mat agitates the metal during itsprogress into the recesses or corners, edges, etc., of the letters orthe mold and forces out any gas or air that hasbecome entrapped orentrained in the metal.

Further, it is obvious that the fluid metal when agitated in this mannerwill more readily flow into corners or narrow and eX- tended paths whichwill not be filled if it is not agitated. Here it is well to point outthat, contrary to the belief and suggestions of some, this method ofcasting gives results very different from those obtained by castingunder pressure of vacuum for the reason that the agitation of the metalnot only creates heat but it also shifts substantially instantly anyportion of metal which has become sufficiently cooled as to be partiallycongealed or whose viscosity has increased to a point where pressurewould not move it. Also, vibration produces a constant distortion of anyportion of fluid metal which would be subject to such a condition thatthe effect of vibration substantially prevents the configuration of anycongealed portion or'the effect of coolin upon the character of theimpressions obtained.

The fact that first class or perfect impressions can be obtained atlower temperatures by vibrating the metal has a decided advantage, bothas to the quality of the finished work as also the cost, because thelower the temperature at which the metal is cast the better, for if thetemperature of the metal is increased above 525 F., deterioration isgreatly increased and oxidized or burnt metal is often the cause ofimperfect castings, particularly half-tones or pictures and shadings.

My invent-ion and its use involves no large expense, maintenance oroperating costs nor increased labor, for the amount of current requiredto operate the vibrator and the-original cost, considering the operativelife of the equipment, are very small.

Having described my invention I claim the following:

1. A method of making printing plates which consists in placing a mat ina mold box, holding the mat in position therein, pouring molten metalinto the mold box and vibrating the mold boX and the metal during theperiod of pouring whereby any warpage of the mat is overcome and aperfect impression obtained.

2. A method of removing gases entrapped between a mat and molten metalpoured thereon to form a stereotype casting, which includes the steps ofplacing the mat in a mold box, pouring molten metal on the mat, andvibrating the metal and the mat whereby the fluid metal displaces gasesremaining in recesses or pores in the surface of the mat.

3. A method of making stereotype castings including the steps of placinga mat in a mold box, holding the mat in a stationary position therein,casting fluid metal in the mold, vibrating the mold and the metal, andregulating the amplitude and frequency of the vibrations during thecasting process to cause the vibrating metal to press the mat firmlyagainst the mold regardless of any warpage in the mat.

4. A method of casting a printing plate including the steps of pouringmolten metal into a mold having a mat therein, and vibrating the moldwhile the metal therein is still plastic to force the metal into thecrevices of the mat against the effect of the surface of the mat, thesurface tension of the molten metal and its viscosity.

5. A method of casting a printing element including placing a mat in amold, pouring molten metal on the mat, vibrating the mold while saidmetal is still plastic, to force the metal into the crevices of said matagainst the effect of the surface of the mat, and the surface tensionand viscosity of the metal in opposing flow of the metal, and continuingthe vibration until the metal is substantially set.

In testimony whereof I have hereunto set my hand, this 26th day ofNovember, 1930, at Lancaster, Ohio.

PAUL E. WHITE.

